• Korean Journal of Soil Science and Fertilizer
• /
• v.48 no.5
• /
• pp.361-371
• /
• 2015

To understand the impact of 2015 spring drought on crop production of DPRK (Democratic People's Republic of Korea), we analyzed satellite and weather data to produce 2015 spring outlook of rice paddy field and rice growth in relation to weather anomaly. We defined anomaly of 2015 for weather and NDVI in comparison to past 5 year-average data. Weather anomaly layers for rainfall and mean temperature were calculated based on 27 weather station data. Rainfall in late April, early May, and late May in 2015 was much lower than those in average years. NDVI values as an indicator of rice growth in early June of 2015 was much lower than in 2014 and the average years. RapidEye and Radarsat-2 images were used to monitor status of rice paddy irrigation and transplanting. Due to rainfall shortage from late April to May, rice paddy irrigation was not favorable and rice planting was not progressed in large portion of paddy fields until early June near Pyongyang. Satellite images taken in late June showed rice paddy fields which were not irrigated until early June were flooded, assuming that rice was transplanted after rainfall in June. Weather and NDVI anomaly data in regular basis and timely acquired satellite data can be useful for grasping the crop and land status of DPRK, which is in high demand.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.9 no.3
• /
• pp.148-152
• /
• 1989

This field experiment was carried out to determine the effects of fertilizer application time in early spring on growth, dry matter (DM) yield, crude protein (CP) content, crude protein yield (CPY), N recovery, acid detergent fibej (ADF) content and DM digestibility (DMD) of grasses for hay. Application times of fertilizer were March 10, 20, 30, April 9. 19, and control (non-fertilized) plot was involved. The fust harvesting data for hay was May 9 (early heading stage) and the regrowth yields were investigated for soiling, 1989. In all fertilized plots, the growth, DM yield, CP, CPY and N recovery of grasses were significantly increased compared with control, and the best grass growth, DM yield, CP, CPY, N recovery and DMD were observed on March 20 and 30 among all fertilized plots. On March 20 and 30 in this experiment, the accumulated temperature was 200 and 280^{\circ}C.$, and the subsoil temperature at 10 cm depth was 8 and 10^{\circ}C.$. Considering the average meteorological condition in Suwon area, the optimum application time of early spring for hay may be recommended from April 10 to 15. i\ulcornerfW3U% (L. westock Experiment Station, RDA. Suwon 440 - 350. Korea)

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.9 no.3
• /
• pp.141-147
• /
• 1989

This experiment was carried out to determine the effects of 13 different application levels of nitrogen(N), phosphorous($P_2O_5$) and potassium($K_2O$) fertilizer at pasture establishment on the winter survival, early spring growth and dry matter(DM) yield, and contents of crude protein(CP) and carbohydrate resewes(CH0-R) of grasses in Suwon from September, 1987 to June, 1988. Winter survival of grasses was high (ca. 90 %) in the plots of N 80 kg, N 120 kg and $K_2O$ application, regardless of $P_2O_5$, while those in zero-N and zero-NPK plots were low as 76 % and 64 %, respectively. Close relationships were observed between winter survival and N & $K_2O$ fertilizer. Early spring growth was vigorous in N-fertilized plots. Heading rate at the first harvest was 50-70 % in all N-plots, regardless of $P_2O_5$ and $K_2O$, while those in zero-N and zero-NPK plots were very low as 20-26 % and 15-18 %,respectively. The DM yield of first harvest was higher in the plots of N 80 kg $ha^{-1}$, regardless of $P_2O_5$ and $K_2O$ levels, and those in zero-N and zero-NPK plots were very low (P < 0.05). The regrowth yleld was not significantly affected by fertilizer levels. The CP content was increased with increasing N level, but CHO-K contents (35-39 %)was not affected by fertilizer levels.Winter survival, early spring growth, DM yield and CP content were significantly influenced by N fertilizer at pasture establishment, regardless of $P_2O_5$ and $K_2O$ application. In this experiment, the compensation effect for spring yield was observed with more N application than usual in next early spring when deficient amount of fertilizer (especially N) was applicated at pasture establishment. Also the optimum application levels of N, $P_2O_5$ and $K_2O$ fertilizer could be recommended as 80, 200 and 70 kg $ha^{-1}$ in new establishing pasture, respectively.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.16 no.2
• /
• pp.161-168
• /
• 1996

This experiment was canied out to determine the effect of cultivar, harvest date and drying method on the changes of moisture content and quality of spring harvest oat(Avena sativa L.) hay. Disign of the experiment was a spilt-split-plot arrangement with early and late cultivars as main plots, early and late harvest dates as sub-plots, and drying agent and tedding as sub-subplots in three replications. Moisture content of early harvest oat was higher than that of late harvest oat by 127.1% dry weight(DW) in 'Swan' and 39.8%DW in 'Foothill'. Moisture content difference between 'Foothill' and 'Swan' was 117.6%DW at early and 204.9%DW at late harvest dates, respectively. Cultivar effect on moisture content of cut oat was higher at late harvest date, but drying method effect was higher at early harvest. Total nitrogen content of early harvest was higher than that of late harvest by 0.70% and that of 'Foothill' was higher than that of 'Swon' by 0.86%. But no difference in total nitrogen content was found between the drying method. ADF and NDF contents were increased at late harvest by 29% and 1 I%, respectively(P<0.05). ADF and NDF contents of 'Swan' were higher than those of 'Foothill' by 2.8% and 4.5%, respectively. No difference in ADF and NDF contents was obtained by drying methods. RFV of early harvest oat hay was 95.1 and 103.8 for 'Swan' and 'Foothill' but late harvest 'Swan' and 'Foothill' showed 74.8 and 85.0, respectively.

• Journal of the Korean Society of Food Culture
• /
• v.31 no.2
• /
• pp.188-193
• /
• 2016

The purposes of this study were to prolong the storage period and maintain quality of kimchi made from spring napa cabbage, which is used less frequently than winter napa cabbage. The results show that the firmness of kimchi from early July, the latest harvest period, was significantly higher than that of kimchi from mid-June. However, as maturation proceeded, no significant difference was observed following the harvest period when kimchi was stored for 8 weeks. Regarding pH and acidity, which are highly related to maturation of kimchi, pH generally decreased from the initial storage period while acidity increased. In the sensory evaluation, appearance was best in kimchi manufactured in late June according to manufacturing and maturation periods (p<0.05). After 4 and 8 weeks of storage, kimchi manufactured in early July had the highest scores with no significant difference. Texture and overall acceptability also showed no significant difference in each processing period.

• The Journal of Korean Philosophical History
• /
• no.32
• /
• pp.337-370
• /
• 2011

The academic circle of the Qing Dynasty has seen a new trend, mostly based on Han-Hak through the event of the publication of "Sagojeyo" and sought a new change in the sector of Spring Autumn-Hak as well. This study is focused on understanding and evaluation of the developmental process of especially the traditional Spring Autumn-Hak view, among some views of "Sagojeyo" by the book. "Sagojeyo" does a critical analysis of Gongyang-Hak and Gokryang-Hak and the interpretation of "Spring Autumn" made by Song-Hak scholars, and which seems a kind of preparatory step to build up a new research methodology for Spring Autumn-Hak. "Sagojeyo" emphasizes the importance of "Jwacijeon" and also points out its weaknesses and strongly demands the acceptance of strengths "Gongyangjeon" and "Gokryangjeon" have in order to compensate such demerits. Even further, it tries to evaluate Spring Autumn-Hak of the Song Dynasty objectively and reasonably as possible with no prejudice. Such analysis attitude made it possible for Spring Autumn-Hak to get a new turning point starting from the publication of "Sagojeyo". The new research methodology that comprehensively judges historical research and fidelity discourse could be one of important achievements discovered in the Han-Hak-centered academic circle in the early Qing Dynasty.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.51 no.4
• /
• pp.322-328
• /
• 2006

A series of methanol extracts from leaf and root parts in spring- and winter-barley plants were assayed to determine their allelopathy and antioxidant activity. The methanol extracts applied on filter paper in a Petri-dish significantly inhibited root growth of Chinese milkvetch (Astragalus sinicus L.) seedlings. Leaf extracts at 25 and 50 g $L^{-1}$ inhibited root growth of Chinese milkvetch seedlings more than root extracts. No difference in phytotoxic effects of spring- and winter-barley seedlings extracts on root growth of Chinese milkvetch was observed. Methanol extracts dose-dependently increased DPPH free radical scavenging activity in vitro. DPPH free radical scavenging activity was higher in the methanol extracts from winter-barley seedlings than in those from spring-barley seedlings, and from leaf extracts than from root extracts. The antioxidant potential of the individual fraction from the methanol extracts of spring-barley seedlings was in order of n-butanol>ethyl acetate>water>chloroform>n-hexane fraction. By means of HPLC analysis, spring-barley (200.62 mg $100g^{-1}$) had more amount of total phenol acid than winter-barley (114.08 mg $100g^{-1}$). Especially, ferulic acid was detected in spring-barley extract (183.46 mg $100g^{-1}$) as the greatest amount. These results suggest that early seedlings of barley plants had potent allelopathy and antioxidant activity, and their activities were differently exhibited depending on plant parts and growing condition.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.12 no.1
• /
• pp.83-90
• /
• 2004

In this study, CT specimens were prepared from spring steel(SUP9) processed shot peening which was room temperature and low temperature experiment. And we got the following characteristics from fatigue crack growth test carried out in the environment of room temperature and low temperature at $25^{\circ}C$, $-30^{\circ}C$, $-50^{\circ}C$, $-70^{\circ}C$,$-100^{\circ}C$, and $-150^{\circ}C$, in the range of stress ratio of 0.05 by means of opening mode displacement. The threshold stress intensity factor range ΔKth in the early stage of fatigue crack growth (Region I)was increased but stress intensity factor range ΔK in the stable of fatigue crack growth (Region II) was decreased in proportion to decrease temperature. It is assumed that the fatigue resistance characteristics and fracture strength at low temperature and high temperature is considerably higher than that of room temperature in the early stage and stable of fatigue crack growth region.

• Journal of the Korean Society of Safety
• /
• v.18 no.3
• /
• pp.1-7
• /
• 2003

In this study, CT specimens were prepared from spring steel(SPS5) processed shot peening. The fatigue crack growth tests were carried out in the environment of the room temperature md low temperature at $25^{\circ}C$, $-30^{\circ}C$, $-50^{\circ}C$, $-70^{\circ}C$ $-100^{\circ}C$ and $-150^{\circ}C$ in the range of stress ratio of 0.05 by means of opening mode displacement. The threshold stress intensity factor range ΔKth in the early stage of fatigue crack growth (Region I) and stress intensity factor range $\Delta$K in the stable of fatigue crack growth (Region II) were decreased in proportion to descend temperature. It was shown that the fatigue resistance characteristics and fracture strength at low temperature are considerable higher than those of mom temperature in the early stage and stable of fatigue crack growth region.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.20 no.4
• /
• pp.243-250
• /
• 2000

Selection of oat variety according to cultivation period is an important to increase productivity of forage crop. To investigate the growth characters and dry matter productivity of oats according to cultivation period, early-maturing oat(EM0) and medium-maturing oat(MM0) variety were sown in spring and autumn at central district of Korea. When oats were cultivated in spring, MMO variety was longer 8 cm in leaf length and wider 5 mm in leaf width than 25 cm and 12 mm of EM0 variety, rexpectively. but in autumn, those were not different between maturities of oat varieties. Plant length of MMO variety was longer 7 cm than that of EM0 Variety in spring cultivation, but in autumn, plant length of EM0 variety was longer 14 cm than that of MMO variety. Heading dates were 20th to 22th May in EM0 variety, and 30th May to 10th June in MMO variety in spring cultivation, and ear of EM0 variety emerged 30th Oct. to loth Nov. but that of MMO variety did not emerge at harvesting day in autumn cultivation. In Spring cultivation, dry matter(DM) yield of EM0 variety was 7,349 kg/ha that was less 56% than 11,466 kg/ha of MMO variety, but In Autumn, was more 15% than 6,575 kg/ha of MMO variety. In conclusion, selection of oat variety in spring and autumn cultivation can be different with cropping system of forage crop, and this trial is suggesting that oat variety could be sown MMO variety in spring and EM0 variety in autumn at central district of Korea. (Key words : Oat variety, Productivity, Cultivation season)